1. Field of the Invention
The present invention relates to a recording paper storage device that is disposed in a recording device like a printer, for storing a rolled recording paper in a replaceable manner.
2. Explanations of the Prior Arts
A recording device like a printer has a paper supply magazine as a recording paper storage device. The paper supply magazine, disclosed in JPA.No.10-291350, has a case body to store a rolled recording paper and a lid. The case body incorporates a paper supply roller. Driven from the moving mechanism in the printing section, the paper supply roller makes rotation to transport the rolled recording paper from the paper supply magazine into the printing section. To surely transport the rolled recording paper, the paper supply magazine has a press mechanism to press the outer surface of the rolled recording paper to the paper supply roller at all times. The press mechanism has a press lever and a spring. The press lever is disposed movable between a press position in which the press lever contacts both edges of a paper holder for biasing the rolled recording paper so that the rolled recording paper is pressed onto the paper-supply roller, and a release position in which the press lever parts from the both edges in order to release the paper holder. The spring is attached to the press lever and the lid. When the lid is open, the press lever is pulled by the spring to move to the release position. Meanwhile, when the lid is closed, the press lever is pressed by the spring to move to the press position, to give a predetermined press force to the both edges of the paper holder.
Since the rotational amount of the lid is large, however, the expansion and contraction of the spring in proportion to its rotational amount makes the spring weak to be deformed in the end. Due to the repetitive opening and closing of the lid, the press force of the press lever becomes non-uniform, which was a problem in reliability.
In order to increase reliability, JPA.No.2001-192521 discloses a link mechanism and a toggle spring to move the press lever in cooperation with opening and closing the lid. The toggle spring is disposed to locate a fulcrum position within a range of movement of the lid, in order to urge the press lever toward the press position or the release position. According to this press mechanism, it is possible to keep the press force constant because the amount of expansion and contraction can be reduced.
However, since the only toggle spring urges the press lever to the rolled recording paper, a large force to move the lid is required around the fulcrum position of the toggle spring. Moreover, when the toggle spring is over the fulcrum position, the press lever moves to the press position at a stroke by its predetermined press force. Owing to this, the press lever catches user's fingers. There is another possibility to cause damage to the both edges of the paper holder after repetitive opening and closing of the lid.